Aromatic polycarbonates are excellent molding materials as products made therefrom have high impact strength, toughness, high transparency, wide temperature limits (high impact resistance below -60.degree. C. and a UL thermal endurance rating of 115.degree. C. with impact), good dimensional stability, high creep resistance and electrical properties which qualify it as sole support for current carrying parts.
Polycarbonates are, however, very difficult to fabricate from melts since such melts have exceptionally high viscosities. Attempts to overcome this difficulty in polycarbonates by employing materials known to reduce the viscosity of other resins have very generally been unsuccessful. Many standard viscosity control agents appear to have little or no effect on the viscosity of polycarbonate. Other compounds known to lower the viscosity of resins cause degradation of polycarbonate resins. Some compounds, conventionally employed to improve the workability of polymers, produce an embrittling effect when they are employed with polycarbonates which are subjected to elevated molding temperatures. Still other materials, while satisfactory stiffness modifying agents for other plastics, are too volatile to be incorporated with polycarbonates since polycarbonates have much higher melting points than many other thermoplastics.